PLK1 and lung cancer: By analyzing the expression profiles of EGFR and PLK1 in lung cancer patients using TCGA data from cBioPortal (Figure 5A), we found that the expression levels of PLK1 and EGFR were correlated positively in lung cancer patients (Spearman factor 0.32, p = 1.65 × 10−9; Pearson factor 0.24, p = 1.159 × 10−5).